As one knows, a patient's pelvis bone may wear out over time at its parts defining the cotyloid cavity, thus requiring the placement of a cotyloid implant reforming the cotyloid cavity in order to receive the prosthetic femoral articulation head.
In order to be placed perfectly in the cotyloid cavity, the cotyloid implant must be impacted in a cavity, which is done using an instrument comprising a gripping head for the acetabular cup and a handling/impacting handle for that acetabular cup.
For example, patent application publication no. WO 2004/069107 describes an acetabular cup with a proximal inner groove and an instrument comprising a gripping head secured to a handle. The gripping head is equipped with radially movable locking tabs, which engage in the groove of the acetabular cup in order to assemble the acetabular cup thereon, and which are capable to be withdrawn using a handle, to release the acetabular cup.
Such an instrument has a complex structure, and is therefore expensive to manufacture. Furthermore, this instrument must be carefully sterilized between two surgical procedures, in particular at the many interstitial spaces comprised by the gripping head, which affects the usage cost of this instrument.
The present invention aims to resolve this drawback.
Patent application publications nos. US 2007/219562, WO 86/05384 and U.S. Pat. No. 6,468,281 describe similar instruments, with gripping heads secured to handles, these instruments further comprising distal bearing heads coming into contact with the bottom of the acetabular cups to distribute the impact force. The same comments as above can be made regarding the assemblies described by these documents.